/**
 * Licensed to Apereo under one or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information regarding copyright ownership. Apereo
 * licenses this file to you under the Apache License, Version 2.0 (the "License"); you may not use
 * this file except in compliance with the License. You may obtain a copy of the License at the
 * following location:
 *
 * <p>http://www.apache.org/licenses/LICENSE-2.0
 *
 * <p>Unless required by applicable law or agreed to in writing, software distributed under the
 * License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
 * express or implied. See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apereo.portal.portlets.permissionsadmin;

import org.springframework.binding.message.MessageBuilder;
import org.springframework.binding.message.MessageContext;
import org.springframework.stereotype.Component;

/**
 * This class validates {@link PermissionDefinitionForm} objects through the magic of Webflow:
 * http://docs.spring.io/spring-webflow/docs/current/reference/html/views.html#view-validation-programmatic-validator
 */
@Component
public class PermissionDefinitionFormValidator {

    public void validateEditPermission(
            PermissionDefinitionForm form, MessageContext messageContext) {

        // ensure at least one principal has been assigned
        if (form.getPermissions().isEmpty()) {
            messageContext.addMessage(
                    new MessageBuilder()
                            .error()
                            .source("principal")
                            .code("please.choose.at.least.one.principal")
                            .build());
        }
    }
}
